Arcadia is a car-centric city, so renting a car is the most convenient way of transportation. However, if you're not willing to rent a car, you can take public transportation via buses or trains. The estimated cost of transportation is around $10-$20 per day, depending on how many places you plan to visit. Driving is about 30 minutes away from downtown Los Angeles.
If you have more time, you can visit the Arcadia Wilderness, an excellent hiking trail. Also, if you want to learn about exotic animals, you can visit the nearby Los Angeles Zoo. If you want to subtract time, you can choose between either the Arboretum or The Huntington, depending on which is more appealing.
Los Angeles International Airport (LAX) is the closest major airport to Arcadia, located about 36 miles southwest. Another option is the Bob Hope Airport (BUR) located about 21 miles north.